This seems to work, I just need to check the values :)
SELECT qryReportDates.ReportDate, Sum(IIf(Format([AwareDate],"yyyy/mm")<=Format([ReportDate],"yyyy/mm") And Format([DateClosed],"yyyy/mm")>=Format([ReportDate],"yyyy/mm"),1,0)) AS [Open]
FROM qryCQA, qryReportDates
GROUP BY...